/Engine/Plugins/Runtime/MeshModelingToolset/Source/ModelingComponents/Public/BaseTools/BaseMeshProcessingTool.h
Register an optional property set with the given VisibilityFunc, and call OnModifiedFunc if any of the properties change
template<class PropSetType> PropSetType * AddOptionalPropertySet ( [TUniqueFunction](API\Runtime\Core\Templates\TUniqueFunction)< bool()> VisibilityFunc, [TUniqueFunction](API\Runtime\Core\Templates\TUniqueFunction)< void()> OnModifiedFunc, bool bChangeInvalidatesResult )